The present invention generally relates to apparatus for testing and checking the air brakes of a tractor trailer, and more specifically to such testing apparatus which interconnects the truck's glad hand to a tank of compressed air.
The air brakes of a truck generally operate at a pressure under 50 PSI. Quite often the air brakes on a truck will fail or will require more pressure than usual to bring the truck to a stop. Various factors, such as cold weather or the type of terrain the truck drives on, contribute to the brake's malfunctioning.
When such a situation occurs, the truck driver will typically bring the truck into a shop and a mechanic will run a hose between a compressed air tank and the truck's brakes line. The mechanic then sends air under extraordinarily high pressure (100-160 PSI) through the hose, thereby causing the brakes to be slammed into braking position with any obstruction that may have caused the problem being displaced by the high pressure air. However, although this procedure may cause the brakes to operate under the extraordinary pressure, the problem may not be completely solved and the brakes may again fail under normal conditions.
In some situations, even the use of high pressure won't cause the brakes to function, and the problem must be diagnosed in an alternate manner. Typically, a diagnostic test will require two mechanics; one to hold the brake pedal down, and another to crawl beneath the truck to observe where the problem is occurring. One mechanic would then depress the brake pedal to permit the compressed air to flow through to the brakes, while the other mechanic observes the brakes and tries to diagnose the problem. Although this solution sometimes works, it does require the use of two mechanics, one of whom does nothing but step on and off the brake pedal, thereby adding labor costs to the repair.
It is therefore a principal object of the present invention to provide a device which permits one mechanic to accurately diagnose a pressure related problem occurring with a truck's air brakes.
It is an additional object of the present invention to provide an air brake diagnostic tool which is easily handled and portable.
It is another object of the present invention to provide an air brake diagnostic tool which is easily and inexpensively manufactured.
Other objects and advantages of the present invention will in part be obvious and in part appear hereinafter.